1. Technical Field
The present disclosure relates to apparatuses and method for supplying power to a handheld surgical device, and more particularly, to a supplementary DC power source to increase the power supplied to a generator within the handheld surgical device.
2. Background of Related Art
Energy-based tissue treatment is well known in the art. Various types of energy (e.g., electrical, ultrasonic, microwave, cryogenic, thermal, laser, etc.) are applied to tissue to achieve a desired result. Electrosurgery involves application of high frequency electrical current to a surgical site to cut, ablate, coagulate or seal tissue. In monopolar electrosurgery, as shown in FIG. 1A, a source or active electrode 2 delivers high frequency energy from the electrosurgical generator 20 to the tissue and a return electrode 2 carries the current back to the generator. In monopolar electrosurgery, the source electrode is typically part of the surgical instrument held by the surgeon and applied to the tissue to be treated. A patient return electrode is placed remotely from the active electrode to carry the current back to the generator.
In bipolar electrosurgery, as shown in FIG. 1B, one of the electrodes of the hand-held instrument functions as the active electrode 14 and the other as the return electrode 16. The return electrode is placed in close proximity to the active electrode such that an electrical circuit is formed between the two electrodes (e.g., electrosurgical forceps 10). In this manner, the applied electrical current is limited to the body tissue positioned immediately adjacent to the electrodes. When the electrodes are sufficiently separated from one another, the electrical circuit is open and thus inadvertent contact with body tissue with either of the separated electrodes does not cause current to flow.
Electrosurgical instruments have become widely used by surgeons in recent years. By and large, most electrosurgical instruments are hand-held instruments, e.g., an electrosurgical pencil, which transfer electrical or electrosurgical energy to a tissue site. As used herein the term “electrosurgical pencil” is intended to include instruments which have a handpiece that is attached to an active electrode and which is used to cauterize, coagulate and/or cut tissue. Typically, the electrosurgical pencil may be operated by a handswitch or a foot switch. The active electrode is an electrically conducting element that is usually elongated and may be in the form of a thin flat blade with a pointed or rounded distal end. Alternatively, the active electrode may include an elongated narrow cylindrical needle that is solid or hollow with a flat, rounded, pointed or slanted distal end. Typically electrodes of this sort are known in the art as “blade”, “loop” or “snare”, “needle” or “ball” electrodes.
As mentioned above, the handpiece of the electrosurgical pencil is connected to a suitable electrosurgical energy source (i.e., generator) which produces the electrical energy necessary for the operation of the electrosurgical pencil. In general, when an operation is performed on a patient with an electrosurgical pencil, electrical energy from the electrosurgical generator is conducted through the active electrode to the tissue at the site of the operation and then through the patient to a return electrode. The return electrode is typically placed at a convenient place on the patient's body and is attached to the generator by a conductive material.
Some electrosurgical procedures utilize electrosurgical forceps that use both mechanical clamping action and electrical energy to affect hemostasis by heating tissue and blood vessels to coagulate, cauterize and/or seal tissue. As an alternative to open forceps for use with open surgical procedures, many modern surgeons use endoscopes and endoscopic instruments for remotely accessing organs through smaller, puncture-like incisions. As a direct result thereof, patients tend to benefit from less scarring and reduced healing time.
Endoscopic instruments are typically inserted into the patient through a cannula, or port, which has been made with a trocar. Typical sizes for cannulas range from three millimeters to twelve millimeters. Smaller cannulas are usually preferred, which, as can be appreciated, ultimately presents a design challenge to instrument manufacturers who must find ways to make endoscopic instruments that fit through the smaller cannulas. Such endoscopic instruments may use monopolar forceps, bipolar forceps or a combination monopolar/bipolar forceps.
Some portable battery powered surgical devices are powered by lithium-ion batteries. As these batteries require charging before use, a lithium-ion battery requires removal of the battery and sterilization in a hydrogen-peroxide system due to the low heat tolerance of lithium-ion batteries. Hydrogen-peroxide sterilization systems cost more money then high-temperature sterilization techniques and are not as widely available in all locations.